JP3975242B2 - Plastic optical component with antireflection film - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plastic optical component having an antireflection film, and more particularly to a plastic optical component such as an eyeglass plastic lens in which an antireflection film having a high evaluation of film performance is applied using a sputtering method.
[0002]
[Prior art]
In recent years, plastics are frequently used in spectacle lenses from the viewpoint of light weight and excellent impact resistance. This spectacle plastic lens has antireflection films on both sides. The antireflection film has a function of preventing surface reflection by the spectacle plastic lens. This is because when the surface reflection occurs, the transmittance of the optical system is lowered, an increase in light that does not contribute to image formation is caused, and the contrast of the image is lowered. Conventionally, an antireflection film for a spectacle plastic lens has been formed as a single layer film or a multilayer film mainly by a vacuum deposition method.
[0003]
[Problems to be solved by the invention]
At present, a film forming method and an apparatus in which an antireflection film is formed on a spectacle plastic lens or the like with a simple configuration by using a sputtering method (or sputtering method) to improve productivity are being proposed. This film forming apparatus includes a sputter film forming chamber in which a different thin film can be produced by exchanging a target in a vacuum vessel. In the sputter film forming chamber without exposing the spectacle plastic lens to the atmosphere, a multilayer film is formed on the lens surface. An antireflection film can be formed, and further, both surfaces of the lens can be formed simultaneously. According to this film forming apparatus, since film formation can be performed simultaneously on both surfaces of the spectacle plastic lens, the film forming conditions on both surfaces of the lens are the same, and there is an advantage that the same film can be formed on both surfaces of the lens. Further, when the multilayer film is deposited on the lens surface, for example, when the film formation is performed by alternately laminating two kinds of films having different properties (a high refractive index material and a low refractive index material), the above-mentioned sputtering is performed. Since it is only necessary to carry out sputter deposition alternately and alternately by replacing two targets by equipping two targets according to the material of each film in the deposition chamber, the multilayer film has such a structure as the deposition apparatus. There is an advantage that the film formation can be easily performed and the thickness of each layer can be accurately controlled.
[0004]
Therefore, the new anti-reflection film for plastic optical components such as eyeglass plastic lens manufactured using the above-mentioned new film forming method and film forming apparatus using the sputtering method has a new multilayer film structure, and the film performance is evaluated. Therefore, it is possible to propose an antireflection film having a high value.
[0005]
In the evaluation of the film performance of the spectacle lens, the interference color is an important evaluation item. The interference color is a color caused by white light interference, and if it is replaced by a spectacle plastic lens with a multilayer antireflection coating, the interference reflected by the reflected light when a transparent thin film with a different refractive index is placed on the lens surface. Is the color. The interference colors of commercially available lenses with an antireflection film are generally roughly classified into three types: blue, violet, and green. Among them, green interference colors are excellent in terms of eye physiology and aesthetics, and are particularly excellent in commercial value. However, there are various technical problems such as film material selection, film thickness setting, and film formation conditions. However, a technique for stably imparting this interference color has not been established yet.
[0006]
An object of the present invention is to meet the above-mentioned demands. A plastic optical component having an antireflection film having a new multilayer film structure, in which an antireflection film is mainly produced by utilizing a sputtering method, and the film performance is highly evaluated. Is to provide.
[0007]
Another object of the present invention is a plastic having a commercially available antireflection film that is used for spectacle plastic lenses, can stably impart a green interference color with the lens, and has excellent eye physiology and aesthetics. It is to provide an optical component.
[0008]
[Means and Actions for Solving the Problems]
The plastic optical component having the antireflection film according to the present invention is configured as follows in order to achieve each of the above objects.
[0009]
First plastic optical component (corresponding to claim 1): A plastic optical component obtained by applying an antireflection film to at least one surface of a plastic substrate, and the antireflection film is a first layer on the plastic substrate side. Is a multilayer film formed by alternately laminating these high-refractive-index substances and low-refractive-index substances. Thus, the total thickness of the antireflection film is included in the range of 4800-5800 angstroms, of which the total thickness of the low refractive index material is 3500 angstroms or more, Further, the multilayer is formed to have a green wavelength interference range of 480 to 550 nm, an excitation purity range of 10 to 30%, a luminous reflectance of 0.7 to 1.8%, and exhibiting a green interference color. Above When the total number of low refractive index material layers is an odd number (3 or more), The thickness of the low refractive index material Or when the total number (4 or more) of low refractive index material layers is an even number, the film thickness of one of the two low refractive index materials located in the intermediate region is In order to obtain the required hardness and durability, the light is formed so as to fall within the range of 0.471λ to 0.511λ, where λ is the dominant wavelength of light.
[0010]
In the above-mentioned plastic optical component, a multilayer antireflection film is designed and manufactured so as to generate a green interference color. Therefore, when the plastic optical component is used as a spectacle plastic lens, it has a commercial value with excellent aesthetics. A high lens can be realized.
[0012]
In the plastic optical component described above, the antireflection film having a multilayer structure in which the first layer is a high refractive index film, the second layer is a low refractive index film, and a high refractive index film and a low refractive index film are alternately formed. Is formed. The thin film of each layer forming the antireflection film is appropriately controlled so that the film thickness and film quality satisfy desirable conditions, and as a result, an antireflection film having high film performance is realized. In addition, a desired antireflection film can be easily produced from the viewpoint of film design. As the antireflection film applied to the plastic substrate, the film performance such as hardness and durability is enhanced by increasing the film thickness of the low refractive index film located in the intermediate region.
[0013]
First 2 Plastic optical components (claims) 2 Corresponding to): above In a plastic optical component, preferably, the high refractive index material is a sputtering method using a target made of zirconium (Zr), titanium (Ti), tantalum (Ta), or an alloy of two or more thereof. The low refractive index material is a metal oxide formed by sputtering using a silicon (Si) target.
[0014]
First 3 Plastic optical components (claims) 3 Corresponding to): above In the plastic optical component, the high refractive index target is preferably configured to contain Si. Thereby, the high refractive index film is formed containing Si, and the hardness and durability of the film are improved.
[0015]
First 4 Plastic optical components (claims) 4 Corresponding to): above In a plastic optical component, preferably, a Si target is provided separately from the target of the high refractive index material when forming the high refractive index material, and these two types of targets are sputtered simultaneously to form the high refractive index material as a mixed film. A film was formed. Also in this case, Si is contained in the high refractive index film, so that the hardness of the film is improved.
[0017]
First 5 Plastic optical components (claims) 5 In each of the plastic optical components described above, when the plastic substrate has a curvature, the antireflection film is formed as a broadband film. As a result, it is possible to reduce interference color unevenness due to a difference in film thickness distribution due to curvature during film formation by sputtering and interference color change due to oblique incidence.
[0018]
First 6 Plastic optical components (claims) 6 In the above plastic optical components, preferably, the plastic base material is a plastic lens base material for spectacles, and the antireflection film having a multilayer film structure is formed on both surfaces of the plastic base material. Configured to be membrane.
[0019]
First 7 Plastic optical components (claims) 7 In the plastic optical component described above, the antireflection film is preferably composed of 10 layers, and the film thickness of the low refractive index material of the sixth layer located in the middle is increased.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
[0021]
In this embodiment, an example of an eyeglass plastic lens is given as an example of a plastic optical component, and an antireflection film formed on both surfaces of the eyeglass plastic lens will be described. The optical component to which the antireflection film according to the present invention is applied is optimally a spectacle plastic lens, but is not limited thereto.
[0022]
FIG. 1 is a schematic cross-sectional view showing a typical example of a film structure of an antireflection film, and FIG. 2 is a configuration diagram showing an example of a sputtering film forming apparatus. The antireflection film is applied to both surfaces of the lens, but FIG. 1 shows a cross-sectional structure of only one surface of the antireflection film for convenience of explanation. An antireflection film having a similar structure is also applied to the other surface of the lens.
[0023]
The plastic substrate 11 shown in FIG. 1 is a substrate for a spectacle plastic lens. For example, CR-39 (diethylene glycol bisallyl carbonate polymer, nd = 1.499) is used as the material of the plastic substrate 11. The surface of the plastic substrate 11 is coated with a hard film 12 for the purpose of increasing the hardness of the surface. For example, an organosilicon resin containing colloidal silica is used for the hard film 12, and details of the composition are described in, for example, Japanese Patent Publication No. 4-55615.
[0024]
The plastic base material of the spectacle plastic lens usually has a curvature and a curved shape. However, in FIG. 1, it is shown in the form of a flat plate for convenience of explanation. When a plastic substrate is curved, the film deposited thereon generally curves along the substrate surface.
[0025]
Since the hard film 12 is coated in this embodiment, the antireflection film 13 applied to the plastic substrate 11 is formed on the hard film. As shown in FIG. 1, the antireflection film 13 according to the present embodiment is configured as, for example, a 10-layer multilayer film. In this antireflection film 13, the lowermost film 131 located on the plastic substrate 11 side is a high refractive index film. Next, a low refractive index film 132 is formed on the high refractive index film 131. Thereafter, these films 133 to 140 are alternately and sequentially formed in the order of the high refractive index film and the low refractive index film. As a result, the first layer, the third layer, the fifth layer, the seventh layer, and the ninth layer 131, 133, 135, 137, and 139 become high refractive index films, and the second layer, the fourth layer, the sixth layer, The antireflection film 13 having a multilayer film structure is formed by laminating the layers 132, 134, 136, 138, and 140 as the low-refractive index films.
[0026]
In the present embodiment, the high refractive index material forming the high refractive index film is, for example, a metal oxide ZrO of zirconium (Zr). ₂ The low refractive index material forming the low refractive index film is, for example, a silicon (Si) metal oxide SiO. ₂ It is. In addition, any metal oxide of titanium (Ti) or tantalum (Ta) can be used as the high refractive index substance. Furthermore, a metal oxide made of an alloy of two or more of zirconium (Zr), titanium (Ti), and tantalum (Ta) can be used as the high refractive index substance. The high refractive index film and the low refractive index film described above are produced using a sputtering method as described later. Therefore, a target of a high refractive index material and a target of a low refractive index material are prepared.
[0027]
The high refractive index film can also be formed as a mixed film containing the above high refractive index substance and Si. By including Si in the high refractive index film, the performance of the film such as hardness and durability can be improved. As a method for making such a mixed film, for example, two methods can be used. The first method is to include Si in the high refractive index target. By performing sputtering film formation using such a target, a high refractive index film containing Si can be deposited. The second method is to provide a Si target separately from the high refractive index material target. The high refractive index target and the Si target are simultaneously sputtered to form a mixed film. The Si target can be used in combination with a low refractive index target.
[0028]
In the antireflection film 13 having the multilayer structure formed as described above, the film thicknesses of the high refractive index film and the low refractive index film of each layer are preferably as follows when λ is 500 nm (nanometers): Is set.
[0029]
The film thickness of the high refractive index film of the first layer is included in the range of 0.075λ to 0.085λ,
The film thickness of the low refractive index film of the second layer is included in the range of 0.115λ to 0.130λ,
The film thickness of the high refractive index film of the third layer is included in the range of 0.177λ to 0.199λ,
The film thickness of the low refractive index film of the fourth layer is included in the range of 0.101λ to 0.114λ,
The film thickness of the high refractive index film of the fifth layer is included in the range of 0.102λ to 0.115λ,
The film thickness of the low refractive index film of the sixth layer is included in the range of 0.471λ to 0.511λ,
The film thickness of the high refractive index film of the seventh layer is included in the range of 0.102λ to 0.115λ,
The film thickness of the low refractive index film of the eighth layer is included in the range of 0.045λ to 0.060λ,
The film thickness of the high refractive index film of the ninth layer is included in the range of 0.270λ to 0.304λ,
The film thickness of the tenth low refractive index film is set so as to be included in the range of 0.244λ to 0.275λ. In the above, the most preferable film thickness value of each layer is the center value in each range.
[0030]
The above-described antireflection film 13 preferably has a total film thickness in the range of 4800 to 5800 angstroms, and more preferably has a total film thickness of the low refractive index film of 3500 angstroms or more. This is to ensure the hardness required for the antireflection film, durability such as wear resistance, adhesion as a film, and the like. In the case of the present embodiment, in particular, the film thickness of the sixth layer low-refractive index film 136 located in the intermediate region is made relatively thick compared to other films, thereby the antireflection film 13. The required film thickness is achieved and the required conditions such as hardness and durability are satisfied. The reason why the film located in the middle among the plurality of low refractive index films is relatively thick is based on the reason that such a structure is suitable in view of the stress of the film.
[0031]
Note that the number of layers of the antireflection film 13 is not limited to the above ten layers. The number of antireflection films having a multilayer film structure is preferably as small as possible from the viewpoint of film productivity, but can be arbitrarily determined in relation to required film performance.
[0032]
Further, as described above, a plastic base material of a normal spectacle plastic lens has a curvature and a curved shape. When the antireflection film 13 having the multilayer film structure shown in FIG. 1 is produced by using a sputtering method as described later on a curved plastic substrate, depending on the curvature of each part of the plastic substrate. A difference in film thickness distribution occurs, resulting in interference color unevenness and interference color change due to oblique incidence. Therefore, in order to reduce such a problem, it is preferable that the above-described antireflection film 13 is designed as a film having broadband characteristics.
[0033]
Next, with reference to FIG. 2, an example of an apparatus for manufacturing the antireflection film 13 using the sputtering method and the manufacturing process will be outlined. FIG. 2 shows a longitudinal section of the main part of the sputter deposition apparatus. According to this sputtering film forming apparatus, it is possible to form the antireflection film 13 having the above-described multilayer film structure on both surfaces of the plastic substrate 11 simultaneously.
[0034]
This sputter film forming apparatus is roughly divided into an introduction chamber 21 for carrying a processing object and a vacuum processing chamber (in which a high refractive index film and a low refractive index film are alternately formed on both surfaces of the plastic substrate 11 ( (Sputter deposition chamber) 22 and pretreatment chamber 23. The introduction chamber 21, the vacuum processing chamber 22, and the preliminary processing chamber 23 are partitioned by gate valves 24 and 25. The gate valves 24 and 25 are opened and closed at an appropriate timing when an object is taken in and out.
[0035]
The substrate holder 26 carried into the sputter deposition apparatus via the introduction chamber 21 is set in the vacuum processing chamber 22 through the gate valve 24. In FIG. 2, illustration of a carry-in / carry-out mechanism for transferring the substrate holder 26 is omitted. The substrate holder 26 has a disk shape, for example. A large number of base material holding holes 26 a are formed in the substrate holder 26. In these holes 26a, a plastic substrate 11 for spectacle plastic lenses is arranged. Since the base material holding hole 26 a is opened on the upper side and the lower side, the plastic base material 11 held in the base material holding hole 26 a faces the upper and lower spaces of the substrate holder 26. As a result, the above-described antireflection film 13 is formed on both surfaces of the plastic substrate 11 by sputtering.
[0036]
More specifically, the sputtering film forming process in the vacuum processing chamber 22 includes a sputtering process for forming a metal thin film and a conversion process for converting the metal thin film deposited in the sputtering process into an oxide thin film. Therefore, the vacuum processing chamber 22 is provided with a sputtering process region 22A and a conversion process region 22B in view of the apparatus configuration.
[0037]
In the vacuum processing chamber 22, the center of the substrate holder 26 is supported by the upper support member 27 and the lower support member 28, and is arranged in a horizontal state. The upper support member 27 and the lower support member 28 are driven up and down by a hydraulic cylinder (not shown) or the like, and are freely rotatable by a built-in motor rotation mechanism. When the antireflection film 13 is formed on the plastic base material 11, the substrate holder 26 is kept rotated at a required rotational speed by the rotational operation of the upper support member 27 and the lower support member 28. Accordingly, a large number of plastic base materials 11 arranged on the substrate holder 26 pass through the sputtering process area 22A and the conversion process area 22B, and the plastic base material 11 undergoes a sputter film formation process in the sputtering process area 22A. The conversion process area 22B is subjected to a conversion process.
[0038]
In the sputtering process area 22 </ b> A, sputtering apparatuses are provided above and below the substrate holder 26. Each sputtering apparatus includes a target 31, a sputtering electrode 32, a sputtering power source 33, a sputtering gas cylinder 34, and a mass flow 35. When the substrate holder 26 rotates and the plastic base material 11 comes between the upper and lower targets 31, the target material emitted from the target 31 in the sputtered state accumulates on both surfaces of the plastic base material 11, and both surfaces of the plastic base material 11. A thin film of the target material is formed. At this time, sputtering gas such as argon gas is introduced by the sputtering gas cylinder 34 through the mass flow 35, and the sputtering atmosphere is adjusted.
[0039]
In the sputter film formation in the vacuum processing chamber 22, the metal oxide ZrO, which is a high refractive index film, is formed on the first layer based on the above sputtering process and the conversion process described later in order to produce the antireflection film 13 described above. ₂ A metal oxide SiO, which is a low refractive index film, is formed on the second layer. ₂ After that, the high refractive index film ZrO up to the 10th layer is formed. ₂ Low refractive index film SiO ₂ Are alternately formed. In the sputtering process region 22A, a metal that is a source of each metal oxide is deposited. In the first sputtering step for forming the first-layer high refractive index film 131, a target made of zirconium Zr is prepared for the target 31, and Zr is formed on both surfaces of the plastic substrate 11. Next, in the sputtering process for forming the second low-refractive index film 132, the target is replaced with another target made of silicon Si, and sputtering is performed, and Si is formed on both surfaces of the plastic substrate 11. Is done. Thus, the antireflective film 13 is produced by alternately stacking the high refractive index film and the low refractive index film by exchanging the target with the material for the high refractive index film or the material for the low refractive index film alternately. Can do. In FIG. 2, a mechanism for exchanging the target is not shown.
[0040]
In the conversion process region 22B, inductively coupled plasma generators are provided above and below the substrate holder 26. The inductively coupled plasma generator includes a high frequency discharge chamber 41, a high frequency coil 42, a matching box 43, a high frequency power supply 44, a reactive gas cylinder 45, and a mass flow 46. When the substrate holder 26 rotates and the plastic base material 11 to be processed comes between the upper and lower inductively coupled plasma generators, the plastic base material 11 is introduced into the oxygen plasma introduced from the reactive gas cylinder 45 through the mass flow 46. The metal (Zr or Si) deposited in the sputtering process is oxidized, and the oxide (ZrO ₂ Or SiO ₂ ).
[0041]
As described above, in the vacuum processing chamber 22, by repeating the sputtering process and the conversion process while replacing the target on both surfaces of the numerous plastic base materials 11 on the substrate holder 26 that is rotatably set inside, The ZrO shown in FIG. ₂ (High refractive index film) and SiO ₂ An antireflection film 13 having a multilayer film structure made of (low refractive index film) is formed.
[0042]
A shielding member 47 is provided inside the vacuum processing chamber 22 to separate the sputtering process region 22A and the conversion process region 22B.
[0043]
In the above-described sputter deposition apparatus, ZrO is a high refractive index film in the sputtering process. ₂ An example of the film forming conditions is as follows.
[0044]
(1) Sputtering gas: Argon gas (Ar) is used, and a flow rate in the range of 380 to 580 cc / min is supplied.
(2) Oxidizing gas: oxygen gas (O ₂ ) At a flow rate in the range of 46-60 cc / min.
(3) Degree of vacuum during film formation: 8.7 × 10 ^-3 Torr.
(4) Sputter output: DC power is supplied within a range of 3.3 to 3.7 kW.
(5) Oxidized gun output: 0.4 kW of radio frequency (RF) power is supplied.
(6) Deposition rate: 320 to 360 Å / min.
[0045]
In addition, in a sputtering film forming apparatus, SiO, which is a low refractive index film in the sputtering process. ₂ An example of the film forming conditions is as follows.
[0046]
(1) Sputtering gas: Argon gas (Ar) is used, and a flow rate in the range of 110 to 190 cc / min is supplied.
(2) Oxidizing gas: oxygen gas (O ₂ ) At a flow rate in the range of 64 to 70 cc / min.
(3) Degree of vacuum during film formation: 2.4 × 10 ^-3 Torr.
(4) Sputter output: DC power is supplied within the range of 5.1 to 5.3 kW.
(5) Oxidized gun output: 0.4 kW of radio frequency (RF) power is supplied.
(6) Deposition rate: 340 to 380 angstrom / min.
[0047]
Regarding the antireflection film in the spectacle plastic lens having the antireflection film 13 obtained as described above, the initial film performance after film formation and the film performance after one month of constant temperature and humidity are shown below.
[0048]
In the above film performance, the wear resistance, adhesion, alkali resistance, heat resistance, acid resistance, artificial sweat resistance and interference color were evaluated and measured in the following manner.
[0049]
(1) Abrasion resistance: A steel wool test was conducted. In this test, the degree of scratching by rubbing the antireflection film with steel wool # 0000 was judged visually.
(2) Adhesiveness: The surface of a plastic lens having an antireflection film is cross-cut at 100 intervals at 1 mm intervals, strongly adhered with cellophane tape, and then peeled off rapidly to determine whether the multilayer antireflection film has been peeled off. Examined.
(3) Alkali resistance: A plastic lens having an antireflection film was immersed in a 10 wt% NaOH aqueous solution for 1 hour, and the erosion state of the surface of the multilayer antireflection film was observed.
(4) Heat resistance: A plastic lens having an antireflection film was placed in an oven for 1 hour and heated to examine whether cracks occurred. The heating temperature was started at 70 ° C. and increased by 5 ° C., and the superiority or inferiority was determined based on the temperature at which cracks occurred.
(5) Acid resistance: 10 wt% HCl aqueous solution and 10 wt% H ₂ SO _Four A plastic lens provided with an antireflection film was immersed in an aqueous solution for 1 hour, and the erosion state of the surface of the multilayer antireflection film was observed.
(6) Artificial sweat resistance: NaCl, Na ₂ S, NH _Four Then, a plastic lens provided with an antireflection film was immersed in an artificially made sweat containing lactic acid at a temperature of 20 ° C. for 24 hours, and the erosion state of the surface of the multilayer antireflection film was observed.
(7) Interference color: The reflected light from the fluorescent lamp was visually observed.
[0050]
The initial film performance of the antireflection film 13 based on the above evaluation / measurement is as follows.
(1) Abrasion resistance was hardly damaged and there was no problem.
(2) As for the adhesion, no peeling was observed on all 100 eyes.
(3) Alkali resistance was not damaged and there was no problem.
(4) As for heat resistance, cracks occurred at 75 ° C.
(5) No change was observed in acid resistance, and there was no problem.
(6) The artificial sweat resistance did not change, and there was no problem.
(7) The interference color was green.
[0051]
Further, the film performance after one month of constant temperature and humidity of the antireflection film 13 based on the evaluation and measurement is as follows.
(1) Abrasion resistance was hardly damaged and there was no problem.
(2) As for the adhesion, no peeling was observed on all 100 eyes.
(3) Alkali resistance was not damaged and there was no problem.
(4) As for heat resistance, cracks occurred at 60 ° C.
(5) No change was observed in acid resistance, and there was no problem.
(6) The artificial sweat resistance did not change, and there was no problem.
(7) No change was observed in the green interference color, and there was no problem.
[0052]
FIG. 3 shows a measurement example of the spectral reflectance curve of the antireflection film 13. As is apparent from this spectral reflectance curve, a low reflectance is achieved in a wide wavelength range of approximately 420 to 740 nm, and a broadband antireflection film is realized. In particular, the reflectance is relatively high in the wavelength range of about 480 to 550 nm.
[0053]
Further, in the antireflection film according to the present invention, the interference wavelength is green by setting the main wavelength range to 480 to 550 nm, the stimulation purity range to 10 to 30%, and the luminous reflectance to 0.7 to 1.8%. It is a system. Here, the “primary wavelength” is an element representing chromaticity by monochromatic display, and a wavelength corresponding to a point where a line connecting a point represented by chromaticity coordinates and a light source intersects a spectrum locus on a chromaticity diagram. In other words, “stimulus purity” indicates how close the point of the main wavelength is to the light point from 0 to the spectral locus, and the closer the point is, the brighter the color. When displaying the color of a reflective object, the luminous reflectance and chromaticity are generally used. Furthermore, when the chromaticity is displayed in a single color, the above-described dominant wavelength and stimulation purity are used. The luminous reflectance is represented by the ratio between the light beam reflected from the object and the light beam incident on the object.
[0054]
In the antireflection film according to the present embodiment having the spectral reflectance curve shown in FIG. 3, the dominant wavelength is 508 nm, the stimulation purity is 22%, the luminous reflectance is 0.963%, and it exhibits a green interference color. It was.
[0055]
In the above description, the method of forming the antireflection film using the sputtering method has been described. However, the antireflection film having a similar multilayer film structure may be formed by other methods such as a vacuum deposition method and a CVD method. it can.
[0056]
In the above embodiment, the antireflection film having a multilayer film structure is applied to both surfaces of the spectacle plastic lens substrate. However, in the case of other plastic optical components, the antireflection film may be applied to only one surface. Is possible.
[0057]
Further, in the above-described embodiment, the first layer of the antireflection film 13 is the high refractive index film 131, but it is not necessarily strictly the first layer. For example, another film may be present between the hard film 12 and the high refractive index film 131. Accordingly, the high refractive index film 131 may be substantially the first layer in the antireflection film 13.
[0058]
【The invention's effect】
As is apparent from the above description, according to the present invention, the first layer is a high refractive index material and the second layer is low on, for example, both surfaces of a plastic substrate such as a spectacle plastic lens, mainly using a sputtering method. An antireflection film having a multilayer structure in which a high refractive index material and a low refractive index material are alternately laminated is formed as a refractive index material, and the film thickness of the intermediate low refractive index material is relatively increased with this antireflection film. Therefore, an antireflection film having highly evaluated film performance can be realized. In addition, since the antireflection film is formed as a broadband film, when the plastic substrate has a curvature, the interference color unevenness due to the difference in film thickness distribution due to the curvature dependency during the film formation by the sputtering method, and the oblique incidence It is possible to reduce the interference color change due to. Furthermore, a green interference color can be stably obtained, and a commercially valuable antireflection film excellent in eye physiology and aesthetics can be produced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the structure of an antireflection film according to the present invention.
FIG. 2 is a configuration diagram of a sputter deposition apparatus for producing an antireflection film according to the present invention.
FIG. 3 is a graph showing a spectral reflectance curve of an antireflection film according to the present invention.
[Explanation of symbols]
11 Plastic substrate
13 Anti-reflective coating
22 Vacuum processing chamber (sputter deposition chamber)
26 Substrate holder
31 targets

Claims (7)

It is a plastic optical component formed by applying an antireflection film on at least one surface of a plastic substrate,
The anti-reflective coating comprises a first layer on the plastic substrate side as a substantially high-refractive index material and a subsequent layer as a low-refractive index material, and alternately switches these high-refractive index material and low-refractive index material. What laminated to the formed multilayer der, total thickness of the antireflection film is included in the range of 4,800 to 5,800 angstroms, and in them the total thickness of the low refractive index material 3500 angstroms, further,
Its main wavelength range is 480 to 550 nm, the stimulation purity range is 10 to 30%, the luminous reflectance is 0.7 to 1.8% and exhibits a green interference color,
On the multilayer film, when the total number of layers of the low refractive index material is an odd number (3 or more), the film thickness of the low refractive index material positioned in the middle , or the total number of layers of the low refractive index material (4 or more) ) Is an even number, the film thickness of the low refractive index material in one of the two layers located in the intermediate region is set to the wavelength of the main light λ so that the required hardness and durability can be obtained. Is included in the range of 0.471λ to 0.511λ,
A plastic optical component having an antireflection film.   The high refractive index material is a metal oxide formed by sputtering using a target made of Zr, Ti, Ta, or a combination of two or more of these, and the low refractive index material is Si 2. The plastic optical component having an antireflection film according to claim 1, wherein the plastic optical component is a metal oxide formed by sputtering using a target of the above.   3. The plastic optical component having an antireflection film according to claim 2, wherein the target of the high refractive index material contains Si.   A Si target was provided separately from the target of the high refractive index material when forming the high refractive index material, and two types of the targets were simultaneously sputtered to form the high refractive index material as a mixed film. 3. A plastic optical component having an antireflection film according to claim 2. When the plastic substrate has a curvature, the antireflection film is formed as a broadband film, and interference color unevenness due to a difference in film thickness distribution due to curvature dependency during sputtering deposition and interference color change due to oblique incidence The plastic optical component having an antireflection film according to claim 1 or 2 , characterized in that The plastic substrate is a spectacle plastic lens substrate, reflection of claim 1, any one of 5 to the antireflection film on both surfaces of the plastic substrate is characterized in that it is deposited Plastic optical component with a protective film. The anti-reflection film is composed of 10 layers, plastic optical component having an antireflection film according to claim 1 or 2, wherein said that by increasing the thickness of the low refractive index material of the sixth layer located in the middle .

Images